Safety-valve



(No Model.)

P; SGHREIDT.

SAFETY VALVE.

Patented Oct. 5,1897.

ms slams PETERS cn. #How-Lune., WASHINGTON, n c.

vadapted to the same form of valve.

Nrrnn STATES PATENT,

FFlCE SAFETY-VALVE.

SPECIFICATION forming part of Letters Patent No. 591,013, datedOctoloci` 5, 1897.

Application filed March 18, 1896. Serial No, 583,802. (No model.)

To all whom it may concern:

Be it known that I, FRANK Scnnninr, a citizen. of the United States, anda resident of Mansfield, in the county of Richland and State of Ohio,have invented certain new and useful Improvements in Safety-Valves, ofwhich the following is a speciiication.

My invention is an improvement in safety and relief valves; and itconsists in approved means by which the fiuid to be controlled isutilized to overcome the external force upon the pressure controllingthe valve, whereby said valve will be rapidly thrown open torinsure afre-e dischargeof the i'luid'under pressure and as rapidly closed whenthe excess of pressure is relieved. l

It also consists in certain details of construction by which the mainobjects of the invention are economically and with certainty attained,all of which will be first fully described in connection with' theaccompanying drawings and then particularly referred to and pointed outin the claims.

Referring to the drawings, in which like parts are indicated by similarreference-letr ters wherever they occur throughout the various views,Figure l is a longitudinal central vertical sectional view of one formof my improved safety-valve. Fig. 2 is a top or plan view of the saine,a portion being broken away to more clearly indicate the means by whichthe spring-pressure of the su pplemental or trigger valve is locked.Fig. 3 is a transverse sectional view through line of Fig. 1, lookingdown upon the main-valve seat. Fig. 4: vis a similar view through thesame line, showing another form of valve-seat Fig. 5 is a modified formof the device shown in the preceding figures and is my preferred form ofvalve for general purposes. i

Referring iirst to Figs. l to 4, inclusive, the valve case or housingproperis composed of the cylindrical shell A, which has a lateraldischarge-branch a. The lower end of this case A is screw-threaded toreceive the member B, which has formed integral with, it the main-valveseat h' and a downwardly-projecting branch lg', which connects to theboiler or other vessel' containing the fluid under pressure. This part Bis connected to the case A by screw-threaded connection, and the top ofthe'case A is closed by a cap AQ which is centrally perforated to passthe 'tubular stein C and has also projecting upwardly from it an arm a',which is perforated at its upper end to receive the pivot, which is thefulcrum of a testing-lever CL2, the bifurcated arms of which pass uponeach side of the arm or stud a and under thehead'cl of the valve-stein dof the trigger-valve D. The head A' has also atubular extension ci?,which receives a screwthreaded set-pin a4, the shaft of which passesthrough one of a series of perforations a5 in the outwardly-projectingflange a of the cylinder A. The purpose of this arrangement is to adjustor regulate the tension of the spring E,\which is compressed between anadjustable plunger c and a piston c, formed in-` l tegral with thetubular stem C for the pur-` pose of regulating the pressure by whichthe main valve F is held to its seat l).

The ange c, in connection with the vsplit ring canda screw-threadeddiskcz, forms a piston within the cylindrical shell A, the parts vbeing, when screwed together, practically integral with the cylinder ortube C' which houses a s` rin0` cl2 which is com ressed between thelower end lof the cylindrical stem C and the top of the valve D.

The cylinder C has a reduced lower end c3,

, which passes through the partition ci of the case' A and seats in theupper extended neck y f of the' main valve F, so that the pressure ofthespring E forcibly holds the valve F to its seat. The valve F has alsoa tubular extension f, which passes through the valve-seat b andVextends down into the branch h'. The valve D has its seat at the lowerand larger end of the cylinder C', and said cylinder has above the valvelateral perforations cdgwhich,

when the valve D is thrown up by pressure within the boiler or othervessel holding the compressed fluid, allows the fluid to pass into achamber as and exert its pressure to throw up the cylinder C. The diskc2 has a series of vertical perforations c5, which admit the fluid underpressurebetween the flange c and disk c2, thus expanding the splitpacking-ring c and making a steam-tight joint between the piston and thecylindrical shell A.

The cylindrical stem C is grooved or corrugated externally, as clearlyseen in Fig. 9, and the loweriend of the stem being screw- IOO threadedand tapped into the cylinder or housing C it is evident that the tensionof the spring d2 may be regulated by screwing the tubular stem C intothe end of the tube C or turning it backward to release the springstension. By this means the valve D is adjusted to its seat with thedesired pressure, and when properly adjusted the adjustment is held by ascrew-threaded pin d2,tapped into a tubular extension alo upon the capA. The point of the screw a9 entering one of the grooves in the tube Clocks the adjustment.

The seat 19,4as seen in Figs. l and 3, has an annular groove b2 from thetop down to the brackets b3, which support the center ring b4, whichserves as a guide for the valve-stem f', while in Fig. 4 the valve-seatis provided with an annular series of perforations for the same purpose.The purpose of making the valve F and valve-seat larger than theunobstructed opening of the branch b is to insure a greater area forsteam pressure through the series of perforations or through the annulargroove b2 to the under side of the valve F to allow a free discharge ofthe fluid under pressure with a very limited upward vmovement of saidValve.

rlhe form shown in Fig. 5 differs from that shown in the precedingfigures inthat the lower member of the caseB extends up above thedischarge-branch d and is screwed onto the lowerend of the case A2. Themain valve F in this View seats upon the upper portion of the branch b,in which it is guided by the wings b5, extending from the lower end ot'its stem. The lower end of the case A2 has a downwardly-cxtendedscrew-threaded neck to receive the packing-n ut auto form a steamtightjoint around the stem c6 of the valveseat, the valve D' in this casebeing inverted and guided by wings extending up into the cylinder C.

In the form shown in Fig. l the diminished end csiits loose enough toallow steam or condensed water to escape from the chamber co8, but thestem in the form shown in Fig. 5,being packed b v the nut a, will notallow 'the steam or condensed water to escape, and in this case a smallhole L12 is bored through the bottom of the cylinder A2, and there arealso perforations @13 in the case A and A2 to permit any steam to escapewhich might leak into the upper part of said case from the chamber a8.

In operation the valve F is held by the spring E to its seat withslightly more pres sure than desired to relieve the boiler, while thetrigger-valve D or D is set to the pressure desired. When this pressureis exceeded, the trigger-valve is thrown up against the pressure of itsspring d2. The steam under pressure then entering the chamber as exertsits pressure to throw the stem C up against the pressure of its springE, when the valve F will quickly open until the pressure is reduced. Sosoon as it is the spring cl2 will throw its Valve D toits seat, cuttingoff the pressure in the chamber as, when the force of the spring E willquickly close the valve upon its seat.

What I claim isl. The combination o'f the main-val ve chamber, the mainvalve having a tubular stem extending into the inlet-passage and atubular extension upon the back of said valve having a valve-seat withinit, a tubular stem having a reduced lower end to pass through thepartition of the main-valve chamber, a seat within the upper tubularextension of the main valve the enlarged upperportion of said stem abovethe partition havinga valve in its lower end and a piston above thevalve forming a pressure-chamber, a tubular follower screwed into saidstem and forming an upper extension thereof, a spring compressed betweensaid follower and said valve to hold it to its seat the tension of saidspring being regulated by the follower, a spring to bear upon the pistonof the tubular stern andhold the main valve to its seat, a followerabove said spring in the upper end of the case, and the t op cap of thecase havin ga screw-thread ed neck to engage the external thread in theupperend of the case and bear upon said follower, whereby the tension ofthe main-valve spring is regulated, substantially as shown anddescribed.

2. The combination of the case having a main-valve chamber, a tubularextension screwed into the upper end of said valvechamber having itslower end perforated, and

a screw-threaded neck or extension surroundling said perforation, atubular stem passing through said neck extending through the top of thecase havinga valve-seat within it, and a piston carried by it to fit thetubular extension, the main valve centrally perforated and having anuppertubular extension to receive the diminished neck of the tubularstem, a packing-n ut to make a steam-joint between the tubularextension of the case and the tu bular stem, a valve in said tubularstemhaving its stem extending outside of the tubular-stem, a spring to holdsaid valve to its seat, a spring bearing upon the piston of the tubularstem to hold the main valve to its seat, and means such as shown forregulating the tension of the valve-springs, substantially as shown anddescribed.

FRANK SCHREIDT. itnessesr J. CLARKE CUsTER, LoUIs P. BENNETT.

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